Various housing are used to protect electronic equipment from environmental conditions and disruptions caused by electromagnetic interference (EMI) or radio frequency interference (RFI). The housings typically have two or more housing parts that are joined together to create an enclosure. Seams or gaps between the housing parts can allow EMI and RFI to penetrate the housing. To prevent EMI and RFI, many housings have some form of compliant gasket or bridge connector connected across the gap or seam between the housing parts. The gasket or bridge, which is often a stocked part, facilitates electrical contact between the housing parts. Beryllium-copper finger stock gaskets are a common type of EMI shielding gasket.
Compliant gaskets and bridge connectors can create many problems. For example, elastomeric gaskets shrink and lose their integrity over time. When gaskets shrink, gaps form between the housing surfaces and increase in size, increasing the potential for EMI and RFI. Gaskets and bridge connectors also make assembly more complicated, and affect the positioning and design of environmental gaskets and other elements that need to be included on the housing parts.
Finger stock gaskets are typically manufactured with tolerances that permit small gaps between the fingers. Although the gaps are relatively small, and are assumed to be insignificant, the gaps are still problematic for many applications.